1. Field of the Invention
The invention relates to a camera module and, more particularly, to a camera module having a movable lens.
2. Brief Description of Prior Developments
As electronic devices continue to become more sophisticated, these devices provide an increasing amount of functionality by providing several applications within the device. One common application included with electronic devices is a digital camera application.
Electronic devices having digital camera applications with a movable lens are known in the art. For example, U.S. Patent Application Publication No. 2007/0247539 discloses a multi-stage lens driving device for use in various electronic devices. The lens driving device moves an optical lens to provide autofocus/zoom capabilities.
FIG. 29 illustrates an example of a conventional autofocus configuration 28A. The autofocus configuration 28A comprises a large sized sensor 36A with a large shutter 38A on top of (or over) the sensor 36A. All of the lenses 39A move during the autofocus operations in this conventional example.
FIG. 30 illustrates another conventional autofocus configuration 300A. The autofocus configuration 300A comprises a complex voice coil motor (VCM) structure which is located around a lens barrel. The autofocus configuration 300A footprint size may be about 9.5 mm×about 9.5 mm. FIG. 31 further illustrates the complex VCM structure of the configuration 300A in an exploded view. The conventional VCM structure may comprise a printed wiring board 301A having a sensor 303A and a driver IC 305A, a sensor holder 307A, an IR glass 309A, a barrel assembly 311A, a base 313A, a first spring 315A, a carrier 317A, a coil 319A, a spacer 321A, magnets 323A, a yoke 325A, a second spring 327A, a frame 329A, and a top cover 331A.
The demand for continuous size miniaturization generates challenges to implement added camera functionality such as autofocus and zoom operations. As such, there is a problem of implementing conventional lens driving devices for movable lenses in small electronic device configurations.
Additionally, conventional electronic devices offer limited functionality due to the demand for miniaturized devices. For example, image stabilization functions have not been widely implemented in electronic devices, such as mobile phones. However, existing mid-range digital still cameras (such as camera models from Panasonic Corporation or Sony Corporation model DSC T9, for example) provide image stabilization functionality. In conventional digital still cameras, a balancing effect can be implemented by moving the optics (lens) or the sensor. Further information regarding Panasonic's optical image stabilization system may be found at http://panasonic.co.jp/pavc/global/lumix/.
FIG. 32 illustrates another conventional image stabilization configuration 400A. In this example, the lens 401A is moved with electromagnetic actuators along x-y guides 403A, 405A. The image stabilization size may be about 20 mm×about 20 mm×about 9 mm.
U.S. patent application Ser. No. 11/267,394, filed on Nov. 4, 2005, which is hereby incorporated by reference in its entirety, illustrates another image stabilization configuration. In this example, the actuator system comprises piezos.
However, conventional configurations do not provide practical size wise configurations for implementation into small electronic devices. Additionally, as consumers demand increased functionality from small electronic devices, there is a need to provide robust and compact configurations having autofocus and/or image stabilization functionality.
Accordingly, there is a desire to provide an improved camera with a movable lens for use in an electronic device.